Double acting vacuum pump



Feb. 6, 1940.' A M. BAB|TCH n 2,189,526

DOUBLE ACTING VACUUM PUMP Filed March 28. 1938 5 q To /NTAKE y yMAN/FOLD rwentor Pstenfedreb. s, 1940 l2,189,526 l l 2,189,526 l DOUBLEAcrn'm VACUUM PUMP Abraham. M. Bahnen, Flint, Mich., minori GeneralMotors CorporatiomlDetroit, Mich.. 'a

corporation o! Delaware Application March 28, 1938, Serial No. 198,380k3 Claims. ((Cl. 230-38) 'I'his invention relates to air. pumps and isinupper closure wall 46 of the body. Atthe lower` tended moreparticularly as an improvement in end of stem 4| it is engagedl by alever extension the air or Vacuum pump constituting a part of or arm 41.This extension is adapted to be ena combined fuel and vacuum pump foruse with gaged by a shoulder 49 of lever 2| .and to `be motor vehicles.the fuel pump being used to suprocked with the lever and Apushed.`upwardly I ply the engine from the fuel reservoir, and the against thediaphragmvstem when thecam l23 suction pump being intended to actua'tea. vehicle 1 rocks the lever 2|. It will thus be seen that this'accessorysuch as the motor of a windshield lever 2| serves to produce:vibrating movements cleaner. l in both diaphragms |3 and 3|. Under theinl 'I'he primary object of the invention is to uence of aspringilengaginglthe body 1 anda l0 utilize both sides of a vibrating pumpdiaphragm part 53'which 'latter also engages thev lever, the Y as pumpchambers whereby a lesser diaphragm lever is held against the cam 23.The'upward stroke produces the required suction. movement of thediaphragm 3| energizes a' spring More specically the inventive ideacontem- 55. The spring 55 is seated within the upper endY plates butminor changes from prior pumps to l of a recess 51 formed in the`diecast top meml5 accomplish the above stated major object. y ber Il. Atits lower endthis spring engages the.

Other objects and advantages will be underdiaphragm. plate 33. W'hen soenergized thev stood from the following description; spring is availableto move the diaphragmdownf UNITEDSTATBS *Pm-1wfil-ritmif.-

In the drawing: wardly after the completion .of the upward Figure 1 isa. view in vertical section of the movement which has been'given it bythe me- 20 novel pump. chanical means associated with the cam. The 1diaphragm 3| is ytherefore made to vibrate. The top member is formedwith an opening 59 in its outer wall. y `This top memberis castto form asocalled surge chamber or inlet. chamber g5. form. l 8|. -This chamberis locatedl beneatha. ilter The drawing shows a combined fuel andsucscreen 63 which latter is heldin position by a tion pump. Thecombined pump is made up of cap 65 and a screw 61. Access to the surgecham; three die castings of which the intermediate or ber from theopening, 591s' afforded only'through' l body part is marked 1. `To thebody 1 is secured the screen 63l -asgis 'shown by the arrows. in 30 k -abottom part 9 and an upper casting No Figure 1. From the surge'chamberavalve 66 of novelty is herein claimed for the fuel pump conventionallform admits air to the chambermechanism. Since pumps of this kind areabove the diaphragm@ This valve may be held in well known it need beonly briey described. position by screws 66 as shown in Figure 3.v $5There is a flexible diaphragm I3 clamped be- Alsofrom the surge chambera'passage 69 leads yu, `tween parts 1 and 9 by cap screws I5. 'I'he toan opening inthe lower surface ofv top member j usual lter cup for thefuel is marked |1 l I, this opening registering with `a. correspondingand at I9 is designated an inlet opening. The' opening in-the topportion of-body-j1.l -The last i Figure 2 is a top rplan view, the coverbeing partly broken away.

Figure 3 is a section online 3--3 of Figure 1.

Figure 4 is a sectional detail of a modified diaphragm is lifted tocreate suction in a pump chamber beneath the diaphragm by means of a'lever 2| rocked by an engine cam.,23, the lever acting through theinstrumentality of a link 25 attached to the diaphragm stem 21. 'Theaction. of the lever and the link 25A energizes a spring 29 whichproduces the'discharge stroke after the completion of the suctionstroke.

The'body 1 and the top member together form the suction pump. ClampedbetweenY these members 1 and is a flexible diaphragm 3|.

Above the diaphragm is a metal disc 33 and beneath the diaphragm is adisc 35, the discs being'attached to the diaphragmas usual. A pocket 31in the lower disc carriestherewithinthe head 39 of a diaphragm lstein4I. The'stem passes through any suitable seal I3 located in an mentionedopening is controlledv by a valve 1|, the valve 1| together with a bore13 admitting air to' the second pump chamber, thechamber beneath thediaphragm.l Theoutlet valve from the second pump chamber is marked 15.`It disfl charges air-through an apertured baille .11 to the intermediatechamber 19 of thebody 1, this `being the chamber Voccupied by the pumpy:operyating mechanism. Chamber 13 is in communication with the enginecasing* receivingthe lever 2| andhousing the cam 23. From the upper pumpchamber a valve 8| discharges into a slop- 50 ing passage.which--togetherwith a registering l passage 36 intheltop of body 11 alsocommunichamber'l 'and with the engine lcasing. A'

dates with By me immun abovedesnbedtne `ammtude of vibration of thediaphragm is materially reduced because of the vacuum conditionpreveiling in one chamber or the other and resisting the diaphragmmovement. It will be obvious that because of the use of the space onboth sides of the diaphragm as pump chambers there is an effectivedisplacement equal to twice that existing in the case of a single actingdiaphragm pump. In the event that the accessory Ydevice to be operatedis a windshield cleaner, a conduit from Ythe suction motor of thecleaner will be connected to inlet opening 59.

In practice the construction may be as shown in Figure 1 where thedischarge from both pump chambers is into chamber 19. Should it be desired to use the engine vacuum for normal operation of the vacuumoperated accessory and to use the present invention as a booster, theexpedient shown .by Figure 4 may be adopted. Here the upper part of bodyi is formed with an outlet passage 81 instead of with the passage 85.Passage 81 is in communication with a passage I9 in the lower wall oftop il'. Passage 89 communicates with a passage 9| plugged as at 93 andleading into the upper pump chamber above the diaphragm 3l. In this formof the invention it is intended that the intake manifold be connected bya suitable conduit with outlet passage 81. A valve 95 opens from passage89 to passage 81. In this form of the invention valve 8l and thepassages 83 and 85 may be omitted. The suction of the manifold tends toopen valve 95 and create suction in the upper pump chamber. The suctionin the upper pump chamber may operate through valve '66 to draw airthrough the surge chamber 6|, and through opening 59 and thereby fromthe windshield cleaner motor. If the engine suction issuicient it maylift diaphragm 3l against the tensionv of spring 55 to such an extentthat no movement is imparted to the diaphragm by the lever 2|. Underthese circumstances the windshield wiper motor is actuated solely bymanifold suction. In the event of failure of manifold suction the springand the lever 2| at once operate the diaphragm and suction is availablefor operating the engine accessory.

I claim:

. 1.v In a double pump, a body, a top. a diaphragm clamped between saidbody and top,

means constituting rigid parts of said body and top to form, togetherwith said diaphragm, upper and lower pump chambers, an inlet valve andan outlet valve in each of saidA body and top to communicate with eachof the respective pump chambers, an inlet chamber in the topcommunicating with the inlet valve of the upper pump chamber,registering passages in the top and body whereby the inlet chambercommunicates with the inlet valve of the lower pump chamber, an outletchamber in the body communicating with the outlet valve of the lowerpump chamber and otherV registering passages in the top and body wherebythe outlet valve of the upper pump chamber communicates with said outletchamber, said inlet chamber adapted to be connected to a suctionoperated accessory and said outlet chamber adapted to be connected tothe atmosphere.

2. The invention defined by claim 1, together with an apertured wallforming a baffle within said outlet chamber through which baille thedischarged gas from the lower pump chamber passes to prevent thetransmission of valve noise.

3. The invention defined by claim 1, said diaphragm being apertured inregistration with said registering passages of the top and body.

ABRAHAM M. BABITCH.

